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Tailoring alumina thin film properties using hydrophilic/hydrophobic copolymer additives
Author(s) -
Isac L.,
Duta A.,
Purghel E.,
Chitanu G. C.,
Mitrea S.,
Pelin I.
Publication year - 2008
Publication title -
physica status solidi (a)
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.532
H-Index - 104
eISSN - 1862-6319
pISSN - 1862-6300
DOI - 10.1002/pssa.200779429
Subject(s) - materials science , acetylacetone , amorphous solid , chemical engineering , crystallinity , copolymer , porosity , cermet , aluminium , polymer chemistry , ceramic , composite material , polymer , organic chemistry , chemistry , engineering
Thin films of alumina were deposited onto aluminium‐treated substrates by pneumatic spray pyrolysis at 250 °C. As precursors, solutions of AlCl 3 dissolved in the mixture water:ethanol = 1:1 were used. As morphology controlling agents, maleic acid based copolymers (HFB/HFL) and/or acetylacetone were added in spraying solutions. The absorptance ( α ) and emittance ( ϵ ) values are those expected for alumina films, as possible matrix in a cermet, used as a solar‐thermal selective absorber. The films have amorphous–crystalline structure and porous morphology. The alumina film composition and crystallinity can be tailored by adding acetylacetone in the spraying solution, when predominantly amorphous structures are obtained. The addition of hydrophobic/hydrophilic copolymer in the precursor solution favours the obtaining of porous aggregates with large, open structures (3.5–4 μm). These porous morphologies are suitable for further infiltration of metallic particles, for preparation of alumina‐based cermets. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)